Abstract: The changes of adverse temperature tolerance during the germination of radish seeds pretreated by different temperatures were studied. Results showed that the vigor of germination remarkably decreased when the seeds were germinated under the temperatures of higher than 35℃ or lower than 15℃. The mild temperature stress could improve the germination ability of radish seed greatly in high temperature（35℃）. The optimal pretreatment low and high temperature are 15℃ and 25℃ respectively. The optimal pretreatment time is 6 hours（at 15℃）. The pretreatment of high temperature (at 30℃，12 hours) also could improve the seed vigor in low temperature subsequently, which shows that the seeds have cross adaptation for heat and chilling stresses.

Key words: radish(Raphanus sativus L.), seed vigor, adverse temperature, tolerance induction, pretreatment, cross adaptation